T  A 

9  0  / 


UC-NRLF 


LIBRARY 


UNIVERSITY  OF  CALIFORNIA. 


Class 


MODERN  METHODS 

of 

WATERPROOFING 


By 

Myron  H.  Lewis,  C.E. 


NEW  YORK 

THE  ENGINEERING  NEWS  PUBLISHING  COMPANY 

1911 


LIBRARY 

OF  THE 

UNIVERSITY  OF  CALIFORNIA. 


Class 


MODERN  METHODS 

OF 

WATERPROOFING 

Concrete  and  Other  Structures 


A  Condensed  Statement  of  the  Principles,  Rules  and  Precautions  to 

be  Observed  in    Waterproofing  and  Dampproofing 

Structures  and  Structural  Materials 


BY 

MYRON  H.  LEWIS,  CE. 

Consulting   Waterproofing   Engineer 


"Civil  Engineers'  Examinations/' 
Popular  Handbook  for  Cement  and  Concrete  Users, " 
"  Waterproofing — An  Engineering  Problem/'  Etc. 


NEW  YORK 

The  Engineering  News  Publishing  Company 
1911 


COPYRIGHTED,  1911, 

BY 
MYRON  H.  LEWIS  AND  NORMAN  W.  HENLEY 


PRESS  OF  THE  PUBLISH KKS  PKINT1NG  COMPANY,  NEW  YOHK,  TJ.   8.   A. 


PREFATORY    NOTE 

IN  the  summer  of  1909,  The  Engineering  News  Publishing  Co. 
reprinted  the  author's  paper,  "  Waterproofing — An  Engineering  Prob- 
lem," read  before  the  Municipal  Engineers  of  the  City  of  New  York. 
The  entire  edition  of  this  reprint  having  been  sold,  and  the  plates 
from  which  same  was  made  not  being  available,  the  present  re- 
print is  substituted  in  response  to  the  public  demand  for  unbiased 
literature  on  the  subject  of  waterproofing. 

This  reprint  forms  Chapter  XXX.  of  the  author's  new  book, 
"  Popular  Handbook  for  Cement  and  Concrete  Users"  (The  Norman 
W.  Henley  Co.,  New  York),  the  material  for  this  chapter  having  been 
condensed  and  arranged  from  the  author's  papers  read  before  the 
Municipal  Engineers  of  the  City  of  New  York;  the  Philadelphia 
Engineers'  Club;  The  Technical  League;  and  from  his  contributions 
on  the  subject  of  waterproofing  to  the  following  periodicals :  Water- 
proofing, New  York;  Cement  Age,  Chicago;  Concrete,  Detroit; 
Cement  World,  Chicago;  Concrete  Age,  Atlanta;  Engineering  News, 
New  York;  Waterproofing  and  Fire  proofing,  Detroit. 

For  more  extended  discussion  on  the  topics  herein  treated  the 
reader  is  referred  to  the  above  papers.  Criticisms,  suggestions,  and 
accounts  of  readers'  experiences  with  waterproofing  materials  and 
problems  are  solicited.  MYRON  H.  LEWIS,  C.E., 

1113  Builders  Exchange  Building, 
March,  1911.  NEW  YORK. 

[5] 
224426 


TABLE  OF  CONTENTS 


PAGE 


Necessity  for  Waterproofing        .  .-..•• 344 

Method  of  Conducting  Work 346 

Importance  of  Inspection      .         .         . 348 

General  Principles  to  be  Followed 349 

Modern  Methods  of  Waterproofing 350 

The  Membrane   Method        .........  350 

Materials  and  Specifications 351 

Table  Giving  Thickness  or  Number  of  Plys  of  Waterproofing    .         .  352 

Application  of  Materials        .         . 356 

The  Integral  Method      .         . 359 

Materials 360 

Workmanship 362 

Instructions  for  Applying  Waterproof  Coatings      .         .         .         .364 

The  Surface  Coating  Method 366 

Sylvester  Process 367 

Paraffine  Process 368 

Bituminous  Process 369 

Cement  Grouting    ..........  369 

Workmanship 370 

Tables  for  Selecting  Method  of  Waterproofing  to  Employ     .         .         .         .371 

Approximate  Cost  of  Waterproofing 374 

Composition  of  Waterproof  Compounds 375 

Bibliography          .         .         . 378 

[7.1 


SECTION  VI 

IMPORTANT  MISCELLANEOUS  DATA 
ON  CONCRETE   CONSTRUCTION 


CHAPTER  XXX 

THE  WATERPROOFING  OF  CONCRETE  STRUCTURES 

The  Necessity  for  Waterproofing. — Modern  Methods  of  Waterproofing. — General 
Conditions  of  the  Work. — Principles  to  be  Followed. — The  Membrane  Method  in 
Detail. — The  Integral  Method  in  Detail. — Waterproofing  by  Means  of  Surface 
Coatings. — Tabular  Outline  of  Modern  Waterproofing  Processes. 

The  Necessity  for  Waterproofing. — In  many  of  the  forms  of 
construction  work  to  which  concrete  is  so  admirably  adapted,  its 
use  brings  with  it  one  inherent  fault — a  fault  for  which  remedies 
have  long  been  sought,  but  which,  until  recent  years,  have  not  been 
found  in  a  practical  form  suited  to  all  the  varied  needs  of  modern 
construction.  This  striking  fault  of  concrete  work  is  its  great  thirst 
for  water,  a  fault  which  varies  in  its  gravity  according  to  the  propor- 
tioning and  mixing  of  materials  and  to  the  nature  of  the  structure, 
it  frequently  being  the  cause  of  extremely  serious  difficulty.  Of  all 
the  opposing  forces  which  constructors  have  had  to  combat  from  time 
immemorial,  none  has  exceeded  in  its  power  for  evil  the  unwelcome 
intrusion  of  water,  and  building  materials  which  in  their  nature 
favor  such  intrusion  must  suffer  in  value  to  the  extent  of  their  per- 
meability or  absorptive  power. 

The  fact  that  in  practice,  concrete  is  frequently  found  to  be 
porous  and  permeable  has  been  one  of  the  leading  checks  in  its 
rapid  development.  Volumes  have  been  written  on  how  the  in- 
gredients might  be  mixed  to  produce  a  watertight  concrete,  but  we 
might  as  well  seek  to  solve  the  problem  of  perpetual  motion  as  to 
try  to  mix  cement,  sand,  and  stone  so  as  not  to  absorb  water. 

1344] 


The  W^rprppftng  *>£  Concrete  Structures 

If  we  could  examine  a  section  of  concrete  under  a  powerful 
microscope,  it  would  appear  to  us  like  an  immense  sieve  through 
which  fine  particles  of  water  flow  with  more  or  less  freedom. 

We  have  seen  water  rise  up  through  concrete  walls  for  many 
feet,  and  it  will  rise  until  the  weight  of  the  water  absorbed  is  equal 
to  the  capillary  attracting  force. 

As  already  stated  in  Chapter  VII,  if  concrete  is  mixed  rich  and 
mixed  wet,  a  high  degree  of  impermeability  can  be  secured.  Mixing 
rich  imposes  greater  barriers  to  the  passage  of  water;  mixing  wet 
minimizes  the  formation  of  blowholes  by  displacing  much  of  the 
extrained  air,  but  neither  mixing  rich  nor  mixing  wet  destroys  the 
"capillary  positive"  property  of  the  concrete  mass.  Its  absorptive 
capacity  has  been  largely  decreased,  but  its  attraction  for  moisture 
has,  however,  not  been  eliminated;  thus  the  water-tightness  secured 
by  rich  and  wet  mixtures,  however  theoretically  correct  the  propor- 
tions might  be,  is  one  of  degree  only,  a  degree  sometimes  approach- 
ing ideal  but  never  reaching  it.  We  cannot  expect  that  a  mixture 
made  of  cement  and  stone,  each  of  which  is  in  itself  "  capillary 
positive,"  or  water-attracting,  can  become  absolutely  proof  against 
the  absorption  of  water  by  the  mere  act  of  mixing,  unless,  indeed, 
the  operation  had  produced  some  phenomenal  change  in  the  very 
nature  of  the  constituent  materials.  By  care  and  diligence,  a 
mixture  may  be  produced  which  is  sufficiently  close-grained  to 
prevent  the  free  transmission  of  water,  prevent  it  sufficiently,  in 
fact,  to  be  all  that  is  required  in  many  forms  of  construction  work. 
But  where  water  absorption,  besides  water  penetration)  is  to  be 
absolutely  prevented,  no  degree  of  mixing,  no  richness  of  mixture, 
will  altogether  answer  the  purpose;  and  yet  in  many  of  the  forms 
in  which  concrete  enters  our  modern  buildings,  it  is  resistance  to 
water  absorption  that  is  required.  Not  merely  water-tightness  in 
the  ordinary  sense  of  the  word,  but  resistance  to  the  ceaseless  en- 
deavors of  atmospheric  moisture  to  find  its  way  by  capillarity  through 
porous  bodies.  Some  counteracting  influence  to  this  tendency  of 
ordinary  concrete  to  take  up  water  by  capillarity,  is,  therefore  what 
is  required  when  dampness  is  to  be  eliminated. 

It  is  true  that  concrete  exposed  to  the  free  passage  of  water  be- 
comes after  a  time  so  clogged  up  by  fine  silt  present  in  the  water 
that  the  permeability  is  greatly  reduced;  and  Hagloch  states  that 

[345] 


Handbook  for  Cement  and  Concrete  Users 

concrete-block  buildings  exposed  to  the  weather  become  water- 
tight in  from  three  to  twelve  years,  a  fact  which  we  must  likewise 
ascribe  to  the  clogging  of  the  surface  of  the  blocks  by  atmospheric 
dust  deposited  by  rain,  and  which  remains  after  evaporation. 

Modern  engineering  or  architectural  practice  should  certainly 
not  sanction  a  practice  of  waiting  for  the  erratic  and  uncertain  hand 
of  time  where  it  is  essential  to  secure  water-tightness  and  damp- 
proofness  in  concrete  structures,  and  in  the  meantime  to  incur  the 
annoying  consequences  that  always  accompany  damp  and  leaky 
structures;  and  yet  this  is  precisely  what  is  being  done  in  numberless 
instances  by  those  who  refuse  to  realize  the  importance  of  water- 
tightness  in  concrete  work,  or  while  realizing  it,  are  willing  through 
motives  of  false  economy,  to  gamble  with  the  future — nearly  always 
at  their  loss. 

The  number  of  mistakes  made  by  inadequate  provision  for 
waterproofing,  and  their  costly  consequences,  running  into  thou- 
sands of  dollars,  should  serve  as  object-lessons  to  those  who  have 
the  design  of  concrete  work  in  hand  and  the  same  degree  of  attention 
and  study  should  be  given  the  subject  of  water-tightness  as  that 
given  to  other  details  of  construction. 

The  importance  of  the  subject  and  the  scarcity  of  literature 
concerning  it  has  induced  the  author  to  cover  the  subject  in  greater 
detail  than  would  otherwise  be  necessary.* 

Method  of  Conducting  the  Work. — Work  Under  Contract.— 
Waterproofing  work  should  be  done,  if  possible,  under  contract  by 
a  specially  skilled  waterproofer,  or  by  the  concern  making  or  supply- 
ing the  material. 

In  a  large  proportion  of  cases,  the  actual  construction  is  left 
largely  to  a  contractor,  sometimes  under  a  more  or  less  loose  guaran- 
tee; often  under  no  guarantee  at  all,  and  frequently  without  the 
least  supervision  being  exercised  on  the  part  of  the  owner.  In  case 
of  trouble  after  the  completion  of  the  work,  the  owner  may  consider 
himself  fortunate  if  he  happens  to  have  a  guarantee  from  a  respon- 
sible contractor  who  values  his  reputation  for  good  work  as  much  as 
he  does  the  cost  of  remedying  the  trouble.  It  is  usually  not  a  difficult 

*  Much  of  this  chapter  has  already  appeared  under  authorship  of  Myron  H. 
Lewis  in  Cement  Era  for  1909—1910,  at  whose  special  request  the  material  was  pre- 
pared and  is  here  rearranged  with  their  permission. 

[346] 


The  Waterproofing  of  Concrete  Structures 

matter  for  a  contractor  to  disclaim  responsibility  and  endeavor  to 
shift  the  burden,  particularly  where  the  cause  of  the  difficulty  cannot 
readily  be  ascertained,  and  where  several  independent  contractors 
were  at  work  on  various  parts  of  the  job  at  the  same  time.  Any 
interference  or  injury  to  the  waterproofing  by  any  but  his  own  men, 
and  without  his  knowledge,  will  naturally  tend  to  absolve  the  water- 
proofer  from  direct  responsibility. 

Any  deviation  from  the  plans  and  specifications  forming  the 
basis  of  the  contract,  failure  to  lay  protecting  masonry  when  re- 
quired, necessary  openings  made  for  pipe  passages  through  walls 
without  the  knowledge  of  the  waterproofer,  will  likewise  relieve  the 
latter  from  his  contract  in  case  of  future  trouble.  This  division  of 
responsibility  has  often  been  the  cause  of  endless  annoyance,  delays, 
and  expensive  litigation.  A  competent  inspector  who  would  look 
after  all  the  details  of  the  waterproofing  from  the  time  preparation  of 
the  surfaces  begin  until  final  completion  of  the  work,  would  avoid  a 
great  deal  of  such  trouble.  If  a  record  is  kept  of  all  the  work  as  it 
progresses,  the  responsibility  for  any  future  trouble  may  then  be 
traced  with  some  degree  of  certainty.  Without  such  record,  which 
is  more  often  omitted  than  kept,  establishment  of  direct  responsi- 
bility is  a  difficult  matter. 

Work  Not  Under  Contract. — A  great  deal  of  waterproofing 
and  dampproofing  work  must  of  necessity  be  done,  not  by  con- 
tract, but  by  the  purchase  of  materials  and  using  same  accord- 
ing to  directions.  Where  the  work  to  be  done  is  not  large,  and 
where  the  services  of  an  experienced  waterproofer  are  not 
available,  this  method  must  be  employed,  although,  as  a  rule,  it 
is  not  so  advisable  as  having  the  work  done  by  contract,  owing 
to  the  unfamiliarity  of  the  purchaser  with  the  material  and  method 
of  application. 

In  all  waterproofing  work  a  great  deal  of  judgment  and  patience 
must  be  exercised  if  good  results  are  to  be  obtained,  and  where 
materials  are  not  applied  by  the  manufacturer  or  by  one  specially 
familiar  with  same,  the  purchaser  or  owner  should  see  that  the 
material  purchased  is  delivered,  and  that  it  be  used  in  accordance 
with  full  and  explicit  directions  furnished  by  the  manufacturer 
or  dealer.  Conditions  on  different  jobs  of  waterproofing  vary 
so  much  that  the  trade  literature  accompanying  materials  can- 

[  347  ] 


Handbook  for  Cement  and  Concrete  Users 

not  be  expected  to  give  sufficient  information  to  cover  all  con- 
ditions, and  consequently  the  purchaser  in  ordering  material 
should  describe  to  the  dealer  in  detail  the  character  of  the 
waterproofing  work  he  has  in  hand,  and  request  that  material 
and  directions  be  sent  specially  adapted  to  that  particular  work. 
The  usual  vagueness  and  indefiniteness  of  such  descriptions  always 
gives  rise  to  unnecessary  delays,  errors  in  shipments,  and  often  in 
failure  of  the  work. 

Importance  of  Adequate  Inspection. — Thorough  inspection  is 
particularly  essential  in  the  bituminous  shield  or  membrane  method, 
where  the  waterproofing  is  to  be  covered  or  backed  up  by  protecting 
masonry  or  other  material,  and  thus  cannot  be  readily  reached  for 
repairs.  In  dampproofing  exposed  walls  of  buildings  by  application 
of  an  asphaltic  coating  on  the  interior  surface  of  the  walls,  inspection 
should  also  be  particularly  rigid  as  failure  means  the  removal  of 
the  plaster  covering.  Furthermore,  the  difficulty  in  tracing  sources 
of  leakage  when  the  waterproofing  is  covered  up  makes  the  repair 
work  more  uncertain  and  costly. 

On  large  works  particularly,  materials  specified  for  waterproofing 
purposes  should  be  subject  to  the  same  degree  of  inspection  and 
tests  as  other  construction  materials.  There  is  nothing  easier  than 
the  substitution  of  poor  materials  for  good  ones  by  irresponsible 
contractors  or  dealers,  particularly  when  the  price  is  much  below 
the  standard  price  for  like  materials.  So  many  of  the  coal  tar  and 
asphaltic  preparations  look  alike,  that  the  quality  of  the  material 
delivered  can  be  ascertained  only  by  subjecting  them  to  specified 
tests,  fixed  according  to  the  character  of  the  work  in  hand.  Water- 
proofing felts  and  other  fabrics  should  also  be  examined  for  defects, 
and  powders  and  other  materials  to  be  introduced  as  a  part  of  con- 
crete work  should  be  tested  and  compared  with  samples  obtained, 
to  see  that  the  material  ordered  is  actually  delivered. 

So  many  instances  of  failures  due  to  various  causes  have  occurred 
that  it  might  be  well  before  proceeding  to  the  detailed  consideration 
of  various  systems  of  waterproofing,  to  review  briefly  the  important 
points  to  be  considered  in  general  to  obtain  permanency  and 
efficiency. 

The  following  general  principles,  if  carefully  followed,  will 
result  in  an  economical,  durable,  and  efficient  work: 

[348] 


The  Waterproofing  of  Concrete  Structures 


GENERAL    PRINCIPLES    TO    BE    FOLLOWED    IN    ALL 
WATERPROOFING 

i st.  In  deciding  upon  a  system  of  waterproofing  for  any  par- 
ticular structure,  study  the  individual  conditions  of  the  problem  in 
hand.  Consider  the  location,  climate,  service,  nature  of  soil,  founda- 
tion, and  all  other  pertinent  data  and  adopt  a  plan  best  suited  for 
the  necessities  of  the  case.  The  "Tabular  Outline"  at  the  end  of 
this  chapter  will  materially  assist  in  deciding  on  the  method  to 
employ  under  given  conditions. 

2nd.  The  portions  of  the  structure  to  be  treated  must  be  so 
designed  and  prepared  that  the  waterproofing  may  be  properly 
applied  thereon;  allowing  sufficient  working  room  for  securing  good 
surfaces  and  providing  for  adequate  drainage  where  water  pressure 
is  to  be  taken  care  of  during  construction. 

3rd.  Complete,  unbroken  continuity  of  the  waterproofing 
stratum  must  be  obtained,  being  allowed  for  in  the  design  and  in- 
sisted upon  in  the  construction.  Any  breaks  in  the  continuity  of 
the  work  will  surely  be  disclosed  in  time  by  leaks. 

4th.  The  material  as  well  as  the  design  should  be  suited  to  the 
individual  conditions  of  the  work,  and  the  delivery  of  the  material 
ordered  should  be  proved  by  tests  and  comparison  with  samples 
previously  submitted. 

5th.  Where  the  designer  or  owner  is  not  familiar  with  this  class 
of  work,  alternative  plans  and  estimates  may  be  called  for  from 
several  responsible  concerns  and  submitted  to  an  impartial  architect 
or  engineer  qualified  to  pass  judgment  on  same. 

6th.  Where  work  is  to  be  done  by  the  immediate  purchaser  of 
materials,  complete  and  explicit  instructions  should  be  obtained 
from  the  dealer  upon  written  request  and  in  conformity  with  the 
conditions  outlined  by  the  purchaser,  and  these  instructions  should 
be  rigidly  followed. 

7th.  The  labor  employed  in  all  waterproofing  work  should  be 
intelligent  and  careful  and  wherever  possible  experienced.  The 
most  satisfactory  way  is  to  have  materials  applied  by  a  representa- 
tive of  the  manufacturer  under  a  guarantee  and  under  supervision 
of  a  competent  inspector. 

[349] 


Handbook  for  Cement  and  Concrete  Users 

8th.  On  all  large  jobs  a  competent  inspector  should  be  present 
from  the  inception  of  the  work  to  its  completion,  and  nothing  should 
be  done,  and  no  tampering  or  interference  allowed  without  his 
knowledge. 

MODERN  METHODS  OF  WATERPROOFING 

Numerous  methods  and  materials  are  now  available  to  keep 
water  and  dampness  out  of  almost  any  structure,  and  under  the 
most  trying  conditions,  and  failure  to  secure  water-tightness  at  this 
date  must  be  looked  upon  as  a  mistake  on  the  part  of  some  one; 
either  the  designer,  constructor,  or  inspector. 

All  the  methods  may,  however,  be  embraced  in  three  general 
classes,  as  follows : 

1.  The  "Membrane"  or  "Elastic"  method;   a  term  introduced 
by  E.  W.  DeKnight.     (See  page  350.) 

2.  The  "Integral"  or  Rigid,  a  term  introduced   by  Myron  H. 
Lewis,  in  1907,  while  editing  the  Waterproofing  Magazine.     Both 
of  these  terms  have  since  been  widely  accepted  by  leading  writers 
on  the  subject.     (See  p.  359.) 

3.  Surface  Coating.     (See  p.  366.) 

These  methods  are  denned  in  detail  in  the  treatment  which 
follows : 

THE  MEMBRANE  METHOD  OF  WATERPROOFING 

The  term  "membrane  method,"  as  employed  by  De  Knight, 
refers  to  an  elastic,  continuous,  bituminous,  impervious  sheet  or 
membrane  which  completely  surrounds  the  structure  to  be  water- 
proofed. This  method  is  adapted  principally  to  waterproofing 
structures  in  course  of  erection,  particularly  those  portions  below 
ground,  such  as  subways,  tunnels,  building-foundations,  retaining- 
walls,  arches,  reservoirs,  etc.  It  is  not  so  well  adapted  to  water- 
proofing structures  already  erected,  or  to  remedy  leaky  conditions 
in  same,  or  to  damp-proofing  exposed  walls  of  superstructures. 
Other  methods  must  be  adopted  for  these  conditions  and  these  will 
be  considered  later. 


The  Waterproofing  of  Concrete  Structures 


Materials. — The  materials  employed  in  the  membrane  method 
of  waterproofing  are : 

1.  Coal  tar  pitch  (applied  hot). 

2.  Commercial  asphalts  (applied  hot). 

3.  Specially    prepared    asphalts    and    compounds    sold    under 
various  trade  names  (applied  cold) . 

4.  Asphalt  mastic  (applied  hot). 

When  merely  dampness  is  to  be  excluded,  any  of  the  first  three 


Brick  wall 

4   inch«». 

Tile   block 

4        •• 

Waterproofing 

H      ••      . 

Brick 

4         » 

Concrete 

30        •• 

r«rr.oa  .«.  pl..« 

''iTH   i.* 

FIG.  115. — Section  of  Building  Substructure,  showing  the  "Membrane"  Method  of 
Waterproofing.     (The  Waterproofing  Co.) 

named  materials  may  be  employed,  two  or  more  coats  being  put  on 
to  insure  thoroughly  covering  the  surfaces. 

When  water  is  to  be  excluded,  these  three  materials  are  employed 
as  cement  or  binders  in  conjunction  with  either  of  the  following 
fabrics : 

(a)  Tarred  felt. 

(b)  Asphalted  felt. 

(c)  Burlap  (ordinary). 

(d)  Burlap  (saturated  with  asphalt). 

(e)  Combinations  of  felt  and  burlap. 

[35i] 


Handbook  for  Cement  and  Concrete  Users 


The  cement  or  binder  acts  as  the  waterproofing  agent,  and  the 
fabric  acts  as  a  reinforcement,  in  addition  to  its  water-resisting 
properties  (when  the  fabric  is  a  saturated  material) . 

The  binding  material  and  fabrics  are  applied  in  alternate  layers, 
one  layer  of  fabric  coated  on  both  sides  with  the  binder  or  cement, 
forming  one  "ply."  The  number  of  ply  to  be  used  depends  upon 
the  local  conditions  and  the  head  of  water  to  be  resisted.  The 
following  table  gives  approximately  the  number  of  ply  required  for 
various  heads  of  water,  using  the  material  stated : 

TABLE  XXXVI. — GIVING  NUMBER  OF   PLY   OF  WATERPROOF- 
ING REQUIRED  FOR  VARYING  HEADS  OF  WATER. 


Head  of  Water. 

MATERIAL. 

Coal  Tar  and 
Felt. 

Commercial 
Asphalt  and  Felt. 

Special  Felts 
and  Compounds. 

Asphalt 
Mastic. 

0 

2 

2 

, 

M  in.  thick 

I 

3 

3 

2 

X    '      " 

2 

4 

4 

3 

%    '      " 

6 

5 

5 

4 

X  '    " 

8 

6 

6 

5 

X  '    " 

10 

7 

7 

6 

X  '    «• 

15 

8 

'     8 

7 

#  '   " 

20 

9 

9 

8 

X  ' 

For  bridges,  4-  to  7-ply,  depending  upon  character  of  traffic;   or  a 
mastic  about  i  inch  thick;  or  part  mastic  and  part  felt  and  cement. 


Completed  WOT* 

""" 


or  ne*  t 


Wo*.* '  Thichness  of  Waterproo 
to  Distinguish  the  Piles 

FIG.  1 1 6. — Showing  Arrangement  of  Laps  in  6-Ply  Waterproofing. 
"  Membrane  Method." 

The  inspector  should  be  careful  to  observe  that  the  number  of 
ply  or  thickness  called  for  in  the  plans  and  specifications  is  actually 
put  into  place. 


The  Waterproofing  of  Concrete  Structures 

Quality  of  Material. —Both  the  cementing  materials  and  the 
fabrics,  in  order  to  be  serviceable  for  waterproofing  operations,  must 
be  elastic  and  durable  and  retain  these  properties  through  the 
range  of  temperature  to  which  they  may  possibly  be  subjected  after 
being  placed  in  the  work. 

In  order  that  materials  of  the  desired  quality  be  obtained,  certain 
requirements  are  usually  outlined  in  the  specifications,  and  it  is 
incumbent  on  the  inspector  to  see  that  these  requirements  are  ful- 
filled as  far  as  it  is  within  his  power  to  do  so.  Laboratory  tests 
should  be  made  on  the  material  delivered  on  the  work  to  determine 
whether  the  physical  and  chemical  requirements  are  satisfied. 

Typical  Specifications  for  Bituminous  Materials. — The  following 
examples  illustrate  some  of  the  requirements  on  important  work. 
The  New  York  Rapid  Transit  Subway  has  this  specification: 

Coal  Tar  Pitch. — Shall  be  straight  run  pitch  which  will  soften 
at  70°  F.,  and  melt  at  100°  F.  The  distillate  oils,  distilled  from  the 
required  grade  of  pitch,  shall  have  a  specific  gravity  of  1.105. 

The  requirements  for  coal  tar  pitch  on  the  Pennsylvania-Long 
Island  Railroad  are  similar  : 

Asphalt. — (a)  Must  be  best  grade  of  Bermudez,  Alcatraz,  or 
Lake  of  equal  quality. 

(b)  It  must  be  either  a  natural  asphalt  or  a  mixture  of  natural 
asphalts. 

(c)  Must  contain  in  the  refined  state  not  less  than  95  per  cent 
natural  bitumen  soluble  in  rectified  carbon  bisulphide  or  in  chloro- 
form. 

(d)  Not  less  than  two-thirds  of  the  total  bitumen  shall  be  soluble 
in  petroleum  naphtha  of  70°  Baume,  or  in  acetone. 

(e)  The  asphalt  shall  not  lose  more  than  4  per  cent  of  its  weight 
at  a  temperature  of  300°  F.,  when  maintained  for  ten  hours. 

(/)  No  injurious  ingredients  shall  be  present. 

An  excellent  set  of  requirements  for  obtaining  a  good  asphalt 
is  found  in  the  specifications  of  the  Chicago  and  Northwestern 
Railroad.  These  are  as  follows: 

1.  The    asphalt    must    be    free    from    coal   tar  or  any  of    its 
products. 

2.  Must  not  volatilize  more  than  one-half  of  one  per  cent  under 
a  temperature  of  300°  F.,  maintained  for  ten  hours. 

23  I  353  ] 


Handbook  for  Cement  and  Concrete  Users 

3.  Must  not  be  affected  by: 

A  2O-per-cent  solution  of  ammonia. 
A  25-per-cent  solution  of  sulphuric  acid. 
A  35-per-cent  solution  of  muriatic  acid. 
A  saturated  solution  of  sodium  chloride. 

4.  Must  not  show  any  hydrolitic  decomposition  when  subjected, 
for  a  period  of  ten  hours,  to  hourly  immersions  in  water  with  alter- 
nate rapid  drying  by  warm  air  currents. 

5.  Range  of  temperature: 

(a)  For  metallic  structure  exposed  to  direct  rays  of  sun. 
Flow  point  not  less  than  212°  F. 

Brittleness — Must  not  become  brittle  at  o°  F.,  when  spread  on 
thin  glass. 

(b)  For  underground  structure  such  as  masonry  arches,  abut- 
ments,- retaining  walls,  building  foundations,  etc. 

Flow  point,  185°  F. 
Brittle  point,  o°  F. 

(c)  Mastic  made  from  (a)  or  (b)  must  be  pliable  at  o°  F. 

Must  not  perceptibly  indent  under  load  of  20  pounds  per  square 
inch  when  at  temperature  of  130°  F. 

6.  Preparation  of  the  asphalt. 

(a)  Care  should  be  taken  that  the  asphalt  is  not  "pitched." 
This  will  take  place  if  heated  above  450°  F.     The  inspector  can  tell 
when  this  point  is  reached  by  the  change  in  color  of  paper  from  a 
bluish  tinge  to  a  yellowish  tinge. 

(b)  The  inspector  can  further  test  for  the  sufficiency  of  the 
cooking  by  putting  in  and  withdrawing  a  stick  of  wood.     The 
asphalt  should  cling  to  it. 

(c)  Should  pitching  occur,  fresh  material  should  at  once  be  added 
to  reduce  the  temperature. 

(d)  When  delays  occur  in  the  work  and  pitching  is  to  be  pre- 
vented, the  fire  should  be  banked  or  drawn  and  fresh  material  added 
to  reduce  the  temperature. 

The  weight  is  also  a  distinguishing  feature  between  the  various 
materials  and  will  aid  the  inspector  in  his  work.  They  are  approxi- 
mately as  follows : 

Coal  tar,  63  pounds  per,  cubic  foot. 

Coal  tar  pitch,  75  pounds  per  cubic  foot. 

[354] 


The  Waterproofing  of  Concrete  Structures 

Trinidad  asphalt  (natural),  80  pounds  per  cubic  foot. 

Trinidad  asphalt  (refined),  93  pounds  per  cubic  foot. 

A  good  coal  tar  pitch  for  waterproofing  should  weigh  70  to  80 
pounds,  and  a  good  asphalt  90  to  95  pounds  per  cubic  foot. 

The  relatively  low  melting-point  will  readily  distinguish  whether 
a  coal  tar  is  being  substituted,  when  asphalt  is  specified,  and  in 
addition  to  the  weight  and  flowing-points  the  characteristic  odor  of 
the  tar  will  detect  substitution. 

Adulteration  of  the  asphalts  with  cheaper  petroleum  products 
and  substitution  of  domestic  asphalts  for  the  Trinidad  or  other 
foreign  brand  usually  specified,  will  also  make  itself  known  in  the 
lower  flowing-point  and  lower  flaming-point,  the  petroleum  oils 
decreasing  these  points  in  accordance  with  the  amount  present. 

When  bituminous  products  are  specified  and  delivered  under 
trade  names  and  are  to  be  applied  cold,  the  flowing-point  cannot  be 
used  as  a  factor  so  readily,  but  such  material  should  also  be  tested 
for  brittleness  under  low  temperature,  and  stability  at  high  tempera- 
ture and  acid  tests  should  be  made  to  determine  their  immunity 
from  ready  attack  by  acid  present  in  the  ground  water. 

Specification  for  As  phallic  Felt. — The  felt  must  be  saturated 
and  coated  with  asphaltic  products  and  must  conform  to  the  follow- 
ing requirements : 

(a)  The  weight  per  100  sq.  ft.  shall  be  from  12  to   14  Ibs., 
saturated,  and  from  5  to  6  Ibs.  unsaturated. 

(b)  The  weight  of  the  saturation  and  coating  shall  be  from 
1.25  to  1.75  times  the  weight  of  the  unsaturated  felt  if  coated  on 
both  sides,  and  from  i  to  1.5  times  the  weight  of  the  unsaturated 
felt  if  coated  on  one  side. 

(c)  The  saturation  shall  be  complete. 

(d)  The  ash  from  the  unsaturated  felt  shall  not  exceed  5  per 
cent  by  weight. 

(e)  The  wool  in  the  unsaturated  felt  shall  not  be  less  than 
25  per  cent  by  weight. 

(/)  Soapstone  or  other  substances  in  the  surface  of  the  felt 
to  prevent  adhesion  shall  not  exceed  .5  Ib.  per  100  sq.  ft.  of  felt. 

(g)  The  saturating  and  coating  materials  shall  remain  plastic 
after  being  heated  to  250  degrees  Fahr.  during  10  hrs.  The  coating 
not  to  crack  when  the  felt  is  bent  double  at  ordinary  temperature. 

[355] 


Handbook  for  Cement  and  Concrete  Users 

(h)  The  felt  shall  -be  soft,  pliable,  and  tough  when  received 
from  the  factory  and  until  placed  in  the  work. 

(i)  The  quotient  obtained  by  dividing  the  tensile  strength  in 
pounds  of  a  strip  i  in.  wide,  cut  lengthwise,  by  the  weight  in  pounds 
of  100  sq.  ft.  shall  not  be  less  than  7. 

'(/)  The  quotient  obtained  by  dividing  the  tensile  strength  in 
pounds  of  a  strip  i  in.  wide,  cut  crosswise,  by  the  weight  in  pounds 
of  100  sq.  ft.  shall  not  be  less  than  3.5. 

(k)  The  strength  saturated  shall  be  at  least  25  per  cent  more 
than  the  strength  unsaturated,  taken  lengthwise. 

The  inspector  should  see  that  all  the  material  delivered  arrives 
in  unbroken  packages  and  contains  the  proper  label  of  the  manu- 
facturer as  specified. 

Application  of  Materials  in  the  Membrane  Method. — In  the 
application  of  the  materials,  certain  fundamental  requirements  must 
be  fulfilled  upon  which  the  final  success  of  the  work  will  largely 
depend,  and  it  is  the  duty  of  the  inspector  to  see  that  such  require- 
ments are  fulfilled.  These  requirements  may  be  conveniently 
classed  under  three  headings,  thus: 

1.  Preparation  of  surface. 

2.  Continuity  of  work. 

3.  Protection  of  waterproofing. 

Preparation  of  Surface. — It  is  difficult  to  make  a  bituminous 
sheet  adhere  to  a  surface  that  is  either  too  rough,  too  wet,  covered 
with  dirt  or  foreign  matter  or  possessing  too  fine  a  glaze  due  to  rich- 
ness of  cement  surface.  It  is,  therefore,  necessary  to  see  that : 

(a)  All  dirt  and  foreign  matter  are  removed  before  waterproofing 
is  applied. 

(b)  That  an  adequate  drainage  system  is  installed  and  main- 
tained, and  that  the  wall  is  dry  when    the   waterproofing  is  ap- 
plied. 

(c)  In  case  complete  dryness  cannot  be  secured,  a  layer  of  felt  in 
addition  to  those  called  for  in  the  specifications  is  first  laid  against 
the  surface. 

Some  specifications  require  that  asphalt  cut  with  naphtha  shall 
first  be  applied  cold. 

(d)  The  surface  should  be  smoothed  off  with  a  trowel,  if  toe 
rough. 

[356] 


The  Waterproofing  of  Concrete  Structures 


(e)  In  case  wall  is  of  concrete,  that  the  concrete  be  thoroughly  set. 

(f)  In  case  wall  is  covered  with  a  fine  skin  of  cement,  see  that  it 
is  roughened  up  to  insure  sticking  of  material. 

(g)  Sharp  projections  on  the  masonry  should  be  removed  or 
they  will  puncture  the  waterproofing. 

(h)  Metal  surfaces  should  be  dry  and  clean,  free  from  rust, 
loose  scale,  and  dirt.  If  previously  coated  with  oil,  same  should  be 

removed   with   benzine  or   other 
suitable   means.     Warming  may 
be  accomplished  by  heated  sand, 
which  is    removed  as   material  is  ap- 
plied. 

Continuity  of  Work. — Lack  of  con- 
tinuity will  be  fatal  to  any  waterproof- 
ing work,  as  water  is  sure  to  find  its 
way  through  any  breaks,  however 
small.  In  order  to  secure  proper  con- 
tinuity, see  that: 

(a)  The  waterproof  sheet  is  applied 
continuously  over  the  whole  surface  to 
be  treated  as  shown  on  the  plans; 
thus  in  building  substructures  it  should 
be  applied  over  all  footings,  walls, 
cellar  bottoms  and  on  the  outer  face  of  all  foundation  walls. 

(b)  That  all  joints  are  broken  properly  at  least  4  inches  on  cross 
joints  and  12  inches  on  longitudinal,  and  at  least  12  inches  lap  left  at 
corners  to  form  good  connections  with  adjoining  sections. 

(c)  Where  it  is  necessary  to  stop  work,  laps  of  at  least  1 2  inches 
should  be  provided  for  joining  on  new  work. 

(d)  Each  layer  of  pitch,  asphalt,  or  other  cementing  material 
must  completely  cover  the  surface  on  which  it  is  spread,  without 
cracks  or  blowholes  or  other  imperfections. 

(e)  The  fabric  must  be  rolled  out  smoothly  and  pressed  over 
the  cementing  material,  so  as  to  insure  its  sticking  thoroughly  and 
evenly  over  the  entire  surface. 

(/)  In  connecting  side  wall  with  floor  work,  the  layers  of  the 
fabric  on  the  sides  should  be  carried  down  on  the  outside  of  the 
ends  of  the  floor  layer  and  lap  at  least  24  inches. 

[357] 


FIG.  117. — Method  of  Water- 
proofing Retaining  Wall. 


Handbook  for  Cement  and  Concrete  Users 

(g)  In  connecting  side  wall  and  roof  work,  the  layers  of  fabric 
of  the  roof  should  be  carried  on  the  outside  of  the  sidewall  layers 
with  at  least  a  24-inch  lap. 

(h)  Before  new  work  is  added  to  old,  the  inspector  should  be 
careful  to  see  that  the  old  surface  is  cleaned  of  all  foreign  matter, 
such  as  cement,  mortar,  or  other  substance  which  finds  its  way  there- 
on. After  cleaning  the  laps,  they  must  be  well  covered  with  fresh 
cementing  material  before  new  layer  of  fabric  is  placed  against  it, 
and  the  new  fabric  should  be  made  to  stick  smoothly  and  evenly 
over  entire  joint  area. 

Protection.— After  the  waterproofing  has  been  put  into  place, 


Waterproofing 


FIG.  118. — Draining  and  Waterproofing  Tunnel  Wall. 

it  must  be  properly  protected  against  injury  from  any  cause  what- 
ever.    Such  injury  is  liable  to  occur  by  puncturing  when: 

(a)  Backfilling  with  earth. 

(b)  Depositing  concrete  against  same. 

(c)  Laying  brickwork  or  rubble  against  same. 
Lack  of  protection  may  also  cause : 

(d)  Bulging  of  waterproofing  from  wall. 

(e)  Cracking  of  same  due  to  bulging. 
(/)  Running  of  material  due  to  heat. 

(g)  Injury  due  to  frost  particularly  when  materials,  brittle  at 
low  temperatures,  are  used. 

Injury  from  any  of  the  above  causes  may  be  avoided  by  placing 

(358] 


The  Waterproofing  of  Concrete  Structures 

against  the  waterproofing  a  protecting  layer  of  cement  mortar  mixed 
in  the  proportions  of  i  part  cement  to  2  1/2  parts  sand. 

This  safety  coat  should  be  placed  as  soon  as  possible  after  the 
laying  of  the  waterproofing,  not  exceeding  1 2  to  24  hours.  Failure 
to  place  such  protection,  if  called  for  in  specifications,  will  be 
sufficient  cause  for  relieving  the  waterproofer  of  responsibility,  if 
under  a  guarantee. 

When  this  safety  coat  is  omitted,  and  backing  of  earth  or  concrete, 
brick  or  stone  masonry  is  to  be  laid  immediately  against  the  water- 
proofing, the  greatest  care  must  be  exercised  that  the  sheet  is  not 
punctured  by  sharp  corners  of  stones  or  bricks. 

When  brick  work  is  placed  against  waterproofing  on  vertical 
walls,  a  slight  space  may  be  left  for  slushing  in  with  mortar  to  avoid 
puncturing.  The  bricks  should  not  be  rammed  up  against  the 
waterproofing  sheet. 

Injury  to  the  waterproofing  might  also  occur  when  the  hydro- 
static pressure  is  very  large,  and  insufficient  weight  has  been  placed 
upon  same  to  secure  it  against  displacement  by  such  pressure. 

Protection  of  the  waterproofing  should  not  stop  with  placing 
the  backfilling  on  same.  Tampering  with  it  should  be  absolutely 
forbidden.  When  openings  or  incisions  in  the  sheet  are  necessary, 
the  inspector  should  be  notified,  and  he  must  see  that  such  places 
are  repaired  in  the  most  thorough  manner.  All  pipe  passages 
should  be  pocketed  and  connections  thoroughly  made.  Such 
places  should  not  be  covered  up  until  the  work  has  been  examined 
by  the  inspector  and  found  properly  executed. 


THE  INTEGRAL  METHOD  OF  WATERPROOFING 

The  term  "  Integral"  refers  .to  those  methods  wherein  the  water- 
proofing material  becomes  an  integral  part  of  the  structure  treated. 
It  includes: 

I.  The  various  methods  employed  in  making  concrete  and 
masonry  impermeable  per  se : 

By  properly  grading  the  materials  and 

(a)  The  addition    of   special   materials  to  the  water    used    in 
tempering  the  cement,  or 

(b)  The  addition  of  special  materials,  dry,  to  the  cement,  or 

[359] 


Handbook  for  Cement  and  Concrete  Users 

(c)  The  use  of  a  ^cement  waterproofed  in  the  process  of 
manufacture. 

II.  The  application  of  materials  thus  prepared  as  a  plaster  or 
coating  to  the  surfaces  to  be  treated,  such  coating  becoming  an 
integral  part  of  the  structure. 

The  Integral  method  is  distinguished  from  purely  surface  appli- 
cations, in  that  the  latter  are  applied  as  a  paint,  and  while  some  of 
the  materials  penetrate  to  a  considerable  extent,  periodic  renewal 
is  required  when  exposed  to  the  elements,  although,  with  some  of 
the  materials,  renewals  may  not  be  required  for  many  years. 

Adaptability  of  the  Integral  Method.— The  "Integral"  method 
of  waterproofing  as  above  outlined,  is  adapted  to  treatment  of 
numerous  conditions.  In  the  form  of  the  coating,  it  is  particularly 
adapted  to  remedying  leaky  conditions  in  substructures  already 
erected;  where  excavations  would  be  too  costly  and  inconvenient. 

Although  the  logical  place  to  apply  waterproof  cement  coatings 
is  on  surfaces  exposed  to  the  water,  yet  owing  to  the  inaccessibility 
of  the  outer  surfaces  for  examination  and  repairs,  the  coatings  are 
applied  to  the  inner  surfaces  as  shown  in  Fig.  117.  It  will  with- 
stand any  ordinary  water  pressure  in  this  position,  if  the  work 
is  properly  executed. 

In  mass  concrete  work,  imperviousness  may  be  secured,  as  al- 
ready stated,  by  the  simple  expedient  of  carefully  grading  the 
materials,  proper  mixing,  and  the  rational  use  of  reinforcement  and 
expansion  joints  to  prevent  the  development  of  cracks.  For  many 
conditions,  no  further  treatment  is  necessary.  Where,  however, 
capillary  absorption  is  to  be  prevented,  and  where  even  dampness 
or  slight  leakage  is  objectionable,  the  introduction  of  special  ma- 
terials in  the  work  is  advisable. 

In  many  cases,  either  the  Membrane  or  Integral  methods  may 
be  employed  with  equally  good  results,  and  the  selection  of  type 
must  be  made  by  the  designer,  after  comparing  their  cost. 

Addition  of  Waterproofing  Material  to  the  Concrete. — Concrete, 
even  when  mixed  according  to  the  most  rigid  rules  and  under  the 
most  competent  supervision,  often  falls  short  of  its  purpose  in 
resisting  water  penetrations.  This  condition,  and  the  inherent 
attraction  of  concrete  for  water,  has  resulted  in  the  appearance  on 
the  market  of  a  large  number  of  compounds  having  the  express 

[360] 


The  Waterproofing  of  Concrete  Structures 


I 


purpose  of  obviating  these  objections.     The  compounds  are  of  a 
proprietary  nature,  and  the  composition  is  kept  secret  by  the  makers. 
The  designer  not  familiar  with  them  should  make  his  selection  of 
material  only  after  carefully  investigating  their  merits. 
These  compounds  may  be  grouped  in  four  classes: 
i.  Powders. — Added  dry  to  cement  before  mixing.     These  are 
usually  of  white,  floury  consistency,  extremely  fine,  and  are  water- 
repellant.     The   water-repellant   properties   are 
imparted   by  the    introduction    of    a    metallic 
stearate,  such  as  lime  soap,  which  is  of  a  fatty 
nature.      Being  so  extremely  fine,  they  have  a 
distinct  void-filling  property,  and  their  uniform 
distribution  in  the   cement  must  give  a  denser 
mixture.     In  addition  to  the  metallic  stearates, 
they  contain  varying  proportions  of   alum  and 
hydrated  lime.      The  latter  materials  are  them- 
selves extensively  used  to  densify  and  waterproof 
concrete  work. 

2.  Cements  are  now  manufactured  un- 
der several  patents,  where  by  the  addi- 
tion of  special  materials  and  special  treat- 
ment    a     water 
repellant  cement 
is  obtained. 

3.  Liquids.  - 
Added  to  water 
employed  in  tem- 
pering the  ce- 
ment. These  are  various  forms  of  metallic  salts,  such  as  chloride 
of  lime  and  oil  emulsions.  Soap  solutions  are  also  employed  for 
this  purpose.  In  the  case  of  the  liquids,  the  waterproofing  prop- 
erty is  imparted  by  the  formation  of  gelatinous  coatings  about  the 
minute  particles  of  the  concrete.  Lime  soaps,  suspended  in  the 
water,  are  also  employed. 

4.  Combinations  of  liquids  and  powders.  The  most  frequent 
form  is  the  addition  of  alum  dry  to  the  cement,  and  the  mixture  of 
soap  solution  to  the  water  employed  in  tempering  the  cement. 
This  is  usually  referred  to  as  the  " Sylvester"  mixture.  In  this  case 


FIG.  119. — Section  of  Building  Substructure  showing  the 
"  Integral  "  Method  of  Waterproofing. 


Handbook  for  Cement  and  Concrete  Users 

waterproofness  is  imparted  by  the  precipitation  of  insoluble  com- 
pounds in  the  voids. 

Where  any  expensive  work  is  to  be  undertaken,  and  the  em- 
ployment of  any  of  these  compounds  is  contemplated,  tests  should 
be  carried  on  to  determine : 

1.  The  effect  on  the  strength  of  the  concrete. 

2.  Their  behavior  when  subjected  to  extreme  ranges  of  tempera- 
ture. 

3.  Their  immunity  to  decomposition  by  various    acids,    etc., 
liable  to  reach  the  concrete. 

4.  The  effect  of  admixture  of  the  materials  to  steel,  embedded  in 
concrete. 

These  materials  being  usually  purchased  under  trade  names, 
and  their  composition  being  secret,  there  is  little  that  the  inspector 
is  capable  of  doing  in  regard  to  them.  He  should,  however,  satisfy 
himself  that  the  material  specified  is  being  used  on  the  work,  by 
identifying  the  packages,  and  noting  that  they  are  unbroken,  and 
contain  the  proper  trade-marks. 

He  should  have  the  directions  furnished  by  the  manufacturer, 
see  that  they  are  explicitly  followed,  and  allow  variations  only  in  case 
unforeseen  conditions  are  encountered,  and  where  special  instructions 
to  cover  them  are  not  at  hand. 

When  the  work  is  being  done  by  the  manufacturer  or  his  repre- 
sentative under  a  guarantee  to  secure  water-tightness,  the  inspector 
should  give  the  latter  free  rein  to  follow  his  own  methods,  provid- 
ing they  are  in  conformity  with  the  general  contract.  He  should, 
however,  keep  a  complete  and  reliable  record  of  the  progress  of  the 
work  for  future  reference. 

Workmanship. — As  previously  stated,  the  treatment  may  consist 
of  adding  waterproofing  material  in  the  body  of  the  concrete,  or  in  a 
coating  or  plaster  applied  to  the  surfaces  to  be  protected. 

In  either  case  the  essential  requirements  for  good  work  are : 

1.  Homogeneity  of  mixture. 

2.  Continuity  of  work. 

3.  Soundness  or  freedom  from  cracks,  etc. 

When  applied  as  a  coating  a  further  requirement  is : 

4.  Bond. — A  uniform  and  efficient  bond  of  coating  to  concrete  or 
masonry  surface  must  be  secured. 

[362] 


The  Waterproofing  of  Concrete  Structures 

Homogeneity. — The  inspector  should  see  that  the  waterproofing 
material  is  uniformly  distributed  throughout  the  work.  Irregular 
distribution  will  result  in  weak  spots,  which  should  be  avoided  as 
much  as  possible. 

Continuity. — He  must  see  that  all  portions  called  for  on  the 


water  proof  i  ng 


Broken  sTone 
Concrete 


FIG.  1 20. — Details  of  Sump  Employed  in  the  Integral  Method  of  Waterproofing. 
Sump  may  be  Sealed  or  Open  as  Required. 

plans  receive  waterproofing  treatment.  Any  omissions  will  break 
the  continuity  of  the  work  and  will  nullify  the  object  which  the 
designer  had  endeavored  to  attain. 

Soundness,   Freedom  from   Cracks,   Etc. — These   are   essential 
requirements  in  successful   waterproofing  work  by  the   Integral 


FIG.  121. — Passing  Pipe  Through  Concrete  Wall.     Method  of  Making 
Water-tight  Joint. 

method,  and  they  should  be  minimized  by  the  use  of  expansion 
joints  and  reinforcements.  The  inspector  should  be  particularly 
careful  that  the  plans  are  properly  carried  out  in  this  respect. 

Bond. — As  already  stated,  the  bond  is  an  important  matter  where 
the  waterproofing  is  done  by  the  application  of  a  coating  of  specially 

1 363  ] 


Handbook  for  Cement  and  Concrete  Users 

prepared  cement  mortar  >to  the  concrete  or  masonry  surface.  The 
coating  should  be  homogeneous,  continuous,  sound,  and  uniform. 
A  good  bond  will  require: 

1.  Correct  mixture  of  the  coating  materials. 

2.  Proper  condition  of  surface  to  receive  the  coating. 

3.  Thoroughness  in  application. 

4.  Careful  connection  of  one  day's  work  to  preceding. 

INSTRUCTIONS     FOR      APPLYING     WATERPROOF 
CEMENT     COATINGS 

In  order  to  carry  out  the  above  provisions  the  following  directions 
are  added:  A  powdered  material  is  here  taken  as  an  example, 
although  most  of  the  directions  apply  equally  as  well  whatever 
character  of  compound  is  to  be  employed.  This  method  of  pro- 
cedure is  followed  by  some  of  the  leading  contractors  doing  this 
class  of  work,  and  if  intelligently  carried  out,  a  durable  and  water- 
tight job  will  be  secured. 

1.  Preparation  of  Coating. 

(a)  To  each  bag  of  cement  add  dry  the  waterproof  compound 
called  for  in  specifications  in  percentage  directed  by  manufacturer. 
Manipulate  until  the  appearance  and  color  indicate  that  a  uniform 
mixture  has  been  obtained. 

(b)  Mix  the  cement  thus  waterproofed  with  sand  in  proportion 
of  i  cement  to  2  sand.     Sand  to  be  absolutely  clean  and  well  graded 
from  coarse  to  fine.     Sand  need  not  be  sharp.     Sand  is  to  be 
moistened,    waterproof    cement    spread    over    it,    and    the  whole 
manipulated  until  a   homogeneous  waterproof   coating   mortar   is 
obtained. 

2.  Preparation  of  Surface. 

(a)  The  old  concrete  surface  should  be  thoroughly  chipped  not 
more  than  two  days  prior  to  application  of  the  coating.     The 
chipping  may  be  greatly  facilitated  by  a  previous  application  of 
muriatic  acid  or  a  bonding  compound,  the  strength  of  the  solution 
depending  upon  the  age  of  the  wall;    or  the  use  of  the  bonding 
material  may  be  deferred  until  the  chipping  has  been  completed. 

(b)  In  case  acid  or  bonding  powders  have  been  employed,  all 
unspent  acid  should  be  removed  by  rigid  application  of  the  hose. 

[364] 


The  Waterproofing  of  Concrete  Structures 

immediately  after  the  acid  treatment  has  reached  a  satisfactory 
stage. 

(c)  The  dust,  dirt,  and  loosened  material  must  be  completely 
removed,   either   by   patient   scrubbing   with   stiff  brushes,   water 
nozzle,  steam  jet,  or  other  suitable  means.     An  absolutely  clean 
surface  should  be  obtained,  not  more  than  twenty-four  hours  ahead 
of  the  application  of  the  coating. 

(d)  All  holes  should  be  filled  up,  large  holes  with  the  waterproof 
concrete,  and  small  holes  with  waterproofed  mortar.     Before  filling 
the  holes,  the  old  surfaces  should  be  drenched  and  slush  coating 
applied,  as  described  below. 

(e)  Just  before  the  main  cement  coating  is  to  be  applied,  the  entire 
wall  should  be  drenched  and  soaked  to  its  full  absorbing  capacity. 

3.  Application  of  Coating. 

(a)  Before  the  wall  shows  marked  signs  of  drying  a  slush  coat- 
ing should  be  applied  quickly  and  uniformly  with  a  palmetto.     This 
slush  coating  should  be  made  by  a  thorough  mixing  of  water- 
proofed cement  in  water,  to  the  consistency  of  cream. 

(b)  Before  the  slush  coating  has  dried,  the  first  application  should 
be  applied  as  a  scratch  coat,  one-fourth  to  three-eighth  inch  thick, 
and  pressure  brought  on  the  trowel  to  push  the  coating  on,  to  form 
a  uniform  bearing.     The  scratch  coating  should  be  made  by  mixing 
one  part  of  waterproofed  cement  to  two  parts  of  clean,  well  graded 
moist  sand,  and  enough  water  to  obtain  proper  consistency. 

(c)  The  scratch  coat  should  be  trowelled  to  a  fairly  good  surface 
and  scratched  before  hardening. 

(d)  Upon  the  scratch  coat,  before  its  final  setting,  the  finishing 
coat  of  sufficient  thickness  to  obtain  a  total  thickness  of  five-eighths 
inch  should  be  applied.     This  should  be  pushed  on  hard  and 
uniformly  trowelled  and  floated  to  a  true  surface,  free  from  pin 
holes,  projections,  or  other  defects.    The  composition  of  the  finished 
coating  shall  be  one  part  waterproofed  cement  to  two  parts  sand, 
well  graded  and  previously  moistened. 

(e)  If  not  feasible  to  apply  finishing  coat  until  after  the  scratch 
coat  has  already  set,  the  latter  must  be  thoroughly  rinsed  and  slush- 
coated  before  finishing  coat  is  applied. 

(/)  The  floating  of  the  finished  surface  shall  be  done  from  the 
bottom  of  the  wall  up. 

[365] 


Handbook  for  Cement  and  Concrete  Users 

(g)  When  the  work  has  been  completed  all  bad  and  defective 
work  shall  be  cut  out  arid  replaced  in  the  same  manner  as  above 
described. 

(h)  When  the  work  has  thoroughly  hardened,  sounding  with  a 
light  hammer  over  the  wall  should  be  resorted  to,  to  discover  any 
loose  or  hollow  portions,  and  same  must  be  cut  out  and  replaced. 

(i)  In  leaving  a  portion  of  work  for  the  day,  the  section  being 
finished  should  be  left  with  straight  edges.  When  the  new  work  is 
to  be  started  the  old  edges  are  to  be  roughened  up  by  chipping  and 
roughing  with  the  trowel  and  the  same  rinsed  and  slush-coated,  as 
already  described. 

WATERPROOFING  BY  MEANS  OF  SURFACE  COATINGS 

The  .third  or  "  Surface  Coating "  method  remains  to  be  con- 
sidered. In  this  method,  the  materials  are  applied  as  a  paint  to 
the  surface  to  be  treated,  and  are  presumed,  upon  completion,  to 
form  a  barrier  to  the  passage  of  water. 

Applicability. — Owing  to  the  comparatively  low  cost  and  ease 
of  application,  this  method  of  waterproofing  has  been  widely 
adopted  and  often,  unfortunately,  under  conditions  wrhere  it  had  no 
right  to  be  employed. 

It  should  not  be  employed  to  keep  water  out  of  basements  or 
substructures  of  buildings,  particularly  when  subject  to  water 
pressure;  its  function  in  building  work  being  to  damp  proof  more 
than  to  water  proof.  Its  use  under  ground  can  be  justified  only 
where  no  permanent  water  is  present  and  ground  dampness  merely 
is  to  be  kept  out.  Its  principal  uses  are: 

1.  To  keep  water  and  dampnessout  of  superstructure  of  buildings. 

2.  To  preserve  building  materials  and  structures  from  decay 
due  to  absorption  of  water  and  other  atmospheric  impurities,  and 
avoid  staining  of  stone  and  efflorescence. 

3.  To  avoid  and  remedy  leaky  conditions  in  tanks,  conduits, 
and  other  water-containing  structures. 

Materials. — A  large  variety  of  materials  is  on  the  market  for 
waterproofing  by  this  method,  but  they  may  be  all  conveniently 
included  in  five  distinct  classes.  A  large  proportion  of  them  are 
made  on  secret  formulas  and  sold  under  trade  names  and  sub- 


The  Waterproofing  of  Concrete  Structures 

stitution  of  inferior  materials  is  often  tempting,  owing  to  the  wide 
variations  in  price. 

The  materials  employed  as  surface  coatings  may  be  grouped  in 
the  following  classes: 

1.  Soap  and  alum  mixtures  applied  in  alternate  coats,  popularly 
known  as  the  "  Sylvester"  process. 

2.  Paraffine  and  other  mineral  bases,  applied  cold  (in  solution), 
or  paraffine  in  melted  condition. 

.3.  Specially  prepared  bituminous  products. 

4.  Cement  grout,  with  or  without  the  addition  of  water  repellants. 

5.  Miscellaneous  materials  of  unknown  composition. 

All  of  the  above,  except  class  3  (bituminous  products),  are 
applied  to  the  surfaces  directly  exposed  to  the  action  of  water.  In 
the  case  of  class  3,  the  application  is  made  to  the  inner  surface  of 
exposed  building  walls,  its  function  in  this  position  being  not  only 
to  dampproof,  but  to  serve  as  an  insulating  film  against  rapid  changes 
of  temperature;  and  also  to  replace  furring  and  lathing,  as  plaster 
may  be  directly  applied  thereon.  This  is  particularly  so  in  the  case 
of  brick  walls.  Furthermore,  the  material  being  protected  from  the 
elements,  a  long  life  is  assured. 

The  Sylvester  Process. — This  process  has  been  principally  em- 
ployed and  is  mainly  adapted  to  coating  the  surfaces  of  tanks, 
conduits,  and  other  water-carrying  structures,  to  render  them  tight. 
It  has  also  been  employed  for  treating  concrete  roofs  and  walls  with 
varying  success.  The  process  consists  of  alternate  applications  of 
solutions,  the  first,  third,  etc.,  coats  of  soap,  and  the  second,  fourth, 
etc.,  of  alum. 

Proportions.— For  soap  solution — 3/4  Ib.  castile  soap  to  i  gallon 
of  water.  For  alum  solution — i  Ib.  alum  to  8  gallons  of  water. 

The  following  precautions  should  be  observed : 

1.  The  soap  and  alum  should  each  be  perfectly  dissolved  before 
using. 

2.  The  surfaces  should  be  clean  and  dry. 

3.  The  soap  solution  should  be  applied  first. 

4.  The  soap  solution  should  be  boiling  hot. 

5.  A  flat  brush  should  be  used. 

6.  Care  should  be  taken  to  avoid  frothing. 

7.  The  first  coat  to  remain  on  24  hours,  or  until  it  is  dry  and  hard. 

[367] 


Handbook  for  Cement  and  Concrete  Users 

8.  Temperature  of  air  to  be  not  less  than  50°  F.  at  time  of 
application. 

9.  Alum  solution  to  be  about  60°  to  70°  F. 

10.  Alum  solution,  second  coat  to  be  applied  thoroughly  over 
the  first  coat. 

11.  Second  coat  allowed  to  remain  24  hours  before  third  coat 
(soap  solution)  is  put  on. 

12.  Two  or  more  coats  of  each  should  be  employed,  depending 
upon  exposure,  pressure,  and  other  local  conditions. 

The  Sylvester  process  imparts  waterproofness  by  the  formation 
of  insoluble  compounds  due  to  chemical  action  between  the  soap 
and  alum  solutions,  the  compounds  filling  the  pores. 

Paraffine. — Cold  Process. — Applicable  to  all  classes  df  masonry 
above  ground,  whether  old  or  new;  adapted  to  protecting  against 
decay,  and  preventing  either  leakage  or  absorption  of  water.  Ma- 
terial is  paraffine  specially  treated  and  dissolved  in  volatile  carrier, 
in  saturated  solution.  A  translucent  liquid  leaving  the  surface  to 
which  it  is  applied  the  same  in  appearance  as  before.  Efficient, 
easily  applied,  and  inexpensive;  covering  capacity  about  125  square 
feet  to  the  gallon  on  first  coat,  and  about  175  feet  to  gallon  on  second 
coat;  two  coats  required.  Materials  best  obtained  from  manu- 
facturers all  ready  for  use.  Has  a  high  penetrating  capacity  into 
masonry  surfaces,  and  after  application  volatile  carrier  evaporates, 
leaving  paraffine  in  the  pores. 

Precautions  to  be  employed  on  the  work : 

1.  See  that  the  material  specified  is  being  used. 

2.  Obtain  explicit  directions  from  manufacturer  and  follow  them. 

3.  Surface  to  be  treated  should  be  smooth  and  freed  from  all 
projections.     Holes  to  be  filled  up. 

4.  Surface  to  be  clean  and  thoroughly  dry,  not  only  on  surface 
but  all  the  way  in. 

5.  Material  to  be  applied  thoroughly;   well  rubbed  in,  filling  all 
corners,  recesses,  etc. 

6.  At  least  two  coats  to  be  applied. 

7.  In  severely  exposed  locations  three  coats  are  advisable. 

8.  Fire  should  be  kept  away  from  the  material  during  application. 
Paraffine. — Hot  Process. — In  this  process,  the  walls  are  first 

treated  with  artificial  heat  and  when  sufficiently  warm,  melted,  hot 

[368] 


The  Waterproofing  of  Concrete  Structures 

paraffine  wax'  is  thoroughly  rubbed  in.  This  is  one  of  the  most 
durable  of  all  the  waterproofing  methods  for  work  exposed  to  the 
weather  and  for  the  preservation  of  building  stones.  It  must 
necessarily  be  applied  by  those  specially  equipped  for  and  exper- 
ienced in  the  work. 

Bituminous  Process. — Employed  for  dampproofing  exposed 
building  walls  of  superstructures  by  application  to  the  interior 
surface  of  such  walls;  for  underground  work  to  prevent  absorption 
of  ground  dampness,  and  also  for  coating  the  covered  faces  of 
building  stones  to  prevent  staining  and  discoloration  due  to  leach- 
ing of  salts  from  masonry  backing. 

Materials  must  possess  a  high  degree  of  elasticity  and  durability, 
and  when 'used  on  walls,  must  have  a  gripping  power  so  that  plaster 
can  be  directly  applied  thereon. 

Materials  specially  prepared  for  these  purposes  obtained  ready 
for  use  under  various  trade  names. 

Precautions  to  be  observed  on  the  work: 

1.  See  that  the  material  specified  is  employed. 

2.  Obtain  directions  of  manufacturers  and  follow  them. 

3.  Surface  to  be  clean  and  dry. 

4.  Two  coats  to  be  applied. 

5.  First  coat  to  be  allowed  to  set  up  before  second  is  applied. 

6.  Work  to  be  well  rubbed  in  in  corners  and  recesses  and  con- 
tinuous throughout. 

7.  When  plaster  is  to  be  applied  directly  on  waterproof  film, 
wall  surface  should  be  left  rough  to  obtain  good  bond. 

8.  Work  to  be  kept  exposed  as  little  time  as  possible  after  com- 
pletion. 

9.  In  applying  plaster  upon  film  see  that  latter  is  not  in  any  way 
injured. 

Cement  Grouting  Processes.— Plain  cement  grout  has  often  been 
employed  for  a  waterproof  coating,  but  owing  to  the  fact  that  such 
coatings  will  absorb  water  by  capillarity  and  also  on  account  of  the 
difficulty  of  making  such  coatings  adhere  without  peeling,  they 
are  not  to  be  highly  recommended.  Several  excellent  prepared 
cement  grouts  are  on  the  market  which  have  been  treated  with 
water  repellants,  and,  having  high  penetrating  qualities,  they  assist 
the  bonding  to  the  masonry  surfaces.  They  are  sold  under  trade 

24  [369] 


Handbook  for  Cement  and  Concrete  Users 

names  and  are  employed  to  impart  a  flat  finish  in  various  colors  to 
concrete  surfaces,  as  well  as  to  dampproof. 

Miscellaneous  Materials, — Numerous  other  materials  are  on  the 
market  for  the  purpose  of  waterproofing  superstructures.  The 
composition  is  secret  and  when  they  are  employed  the  inspector 
should  follow  the  directions  of  the  maker.  He  should,  however, 
see  that  in  any  case  at  least  two  coats  of  any  material  are  applied. 
It  is  almost  impossible  to  obtain  a  surface  free  from  pinholes  and 
other  defects,  on  the  first  application. 

Workmanship. — Whatever  method  is  employed  the  inspector 
should  always  see  that  the  surface  is  properly  prepared  and  that  the 
application  is  continuous  throughout.  Any  omissions  at  corners, 
cornices,  around  windows  and  other  points  easily  accessible  may 
prove  fatal  to  the  final  success  of  the  work. 

As  f6r  the  preparation  of  surfaces,  they  should  always  be  clean 
and  free  from  foreign  matter.  Where  cement  coatings  are  employed 
and  the  waterproofing  depends  upon  the  setting  of  the  cement,  the 
surfaces  should  be  damp  or  wet,  so  that  the  water  necessary  for  the 
setting  will  not  be  absorbed  by  the  masonry.  WTiere  the  water- 
proofing depends  upon  the  penetration  of  the  material  into  the 
pores,  the  surface  should  be  dry  to  increase  the  penetration  as  much 
as  possible. 

Surfaces  should  generally  be  smooth,  holes  filled  up  and  pro- 
jections removed.  Projections  are  likely  to  be  injured  by  scaffold- 
ing and  to  admit  water  at  such  points.  Not  only  does  a  smooth  sur- 
face make  the  application  easier  and  more  certain,  it  is  also  more 
economical  in  material. 

In  the  bituminous  process,  however,  where  the  material  is  applied 
on  the  inner  surface  of  exposed  walls  and  plaster  is  to  be  applied 
directly  on  the  waterproof  film,  the  surface  should  be  rough.  This  is 
necessary  in  order  that  the  plaster  may  properly  bond  to  the  treated 
surface.  Joints  in  brickwork  form  excellent  keys  for  such  bonding 
and  have  been  taken  advantage  of.  A  large  number  of  brick  build- 
ings have  been  treated  by  this  process. 

HOW  TO   USE    THE   TABLE 

The  accompanying  table  has  been  prepared  with  a  view  of  con- 
densing into  small  space  the  principal  features  of  modern  water- 

[370] 


The  Waterproofing  of  Concrete  Structures 


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372] 


The  Waterproofing  of  Concrete  Structures 

proofing  processes  as  applied  to  varying  conditions,  and  to  enable 
one  having  a  waterproofing  problem  to  solve,  and  not  familiar  with 
the  subject,  to  pick  out  the  method  most  suitable  without  having  to 
read  up  the  whole  subject. 

As  previously  stated,  the  method  must  be  suited  to  the  con- 
ditions of  the  problem  if  good  results  are  to  be  had.  In  numer- 
ous cases  more  than  one  method  may  be  employed  with  good 
results  and  in  such  cases  the  methods  have  been  given  in  order  of 
their  desirability.  Local  conditions,  however,  may  make  the  order 
of  preference  different. 

Use  of  the  Table. — The  table  is  divided  into  13  columns  as  num- 
bered on  bottom. 

Columns  3  and  5  give  the  methods  of  waterproofing  for  the 
different  structures  listed  in  columns  i  and  2.  These  methods  are 
listed  by  key  letters  as  A,  B,  C,  etc.,  the  essential  features  of  which 
are  described  in  columns  7  to  13. 

Column  3  gives  the  method  of  waterproofing  that  may  be  pro- 
vided for  in  plans  and  specifications  for  new  structures  or  which 
may  be  employed  before  the  construction  work  has  advanced 
too  far. 

Column  5  gives  the  methods  available  for  the  structures  already 
erected  and  for  remedying  leaky  conditions  in  such  structures.  The 
fact  that  a  method  is  not  listed  in  column  5  means  that  it  is  not  ad- 
visable to  use  it  for  old  structures. 

As  a  practical  example  in  using  the  table,  suppose  it  is  desired 
to  dampproof  the  walls  of  a  new  brick  building  which  is  to  be 
erected  and  also  to  waterproof  the  foundation,  which  is  in  wet 
ground. 

To  Find  the  Method  from  the  Tables.— Look,  up  columns  i  and  2 
for  exposed  walls;  methods  given  are  D,  By  and  C,  in  order  of  de- 
sirability. Now  look  in  column  No.  7  and  those  following  for 
description  of  the  methods  D,  B,  and  C. 

For  the  foundation  to  resist  water  pressure  under  walls,  G,  K, 
L,  M,  are  given  in  order  of  desirability,  but  G  is  omitted  if  walls  are 
not  reinforced.  The  remarks  point  out  some  special  features  such 
as  for  L  and  M,  "Asphalt  not  to  be  used  in  ground  polluted  by  gas 
drip,  oils,  etc.,  that  injuriously  affects  it.  This  is  an  important 
precaution." 

[  373  ] 


Handbook  for  Cement  and  Concrete  Users 

It  is  not  claimed  that  the  arrangement  of  methods  will  in  all 
cases  be  decisive  or  that  some  methods  not  listed  may  not  be  em- 
ployed ;  but  the  use  of  the  table  will  prevent  such  glaring  but  frequent 
mistakes  as  using  a  surface  coating  for  sub-surface  work  or  using  a 
wash  on  the  inside  of  cellar  walls,  to  waterproof  against  pressure 
and  in  other  ways  prevent  the  use  of  wholly  unfit  methods. 


APPROXIMATE    COST    OF   WATERPROOFING 

The  following  table  gives  approximate  cost,  of  different  classes 
of  waterproofing  which  may  be  used  as  a  basis  for  comparing  relative 
economy  of  the  methods  selected  from  the  table: 

A. — Sylvester  process,  1/2  cent  to  4  cents  per  square  foot. 

B,  D. — Dampproofing  masonry  walls,  2  coats  applied  in  place, 
2  cents  to  4  cents  per  square  foot. 

C. — Melted  para  nine,  5  cents  to  8  cents  per  square  foot. 

F. — Adds  about  10  per  cent  to  the  cost  of  untreated  mass  con- 
crete. 

G. — Cement  coatings  with  waterproofing  compounds;  i  in.  on 
floors,  1/2  in.  to  3/4  in.  on  walls,  8  cents  to  30  cents  per  square  foot, 
depending  upon  conditions. 

/. — Hot  coal  tar,  pitch,  and  felt.  Horizontal  surfaces:  first  ply, 
$2  to  $4  per  square  (100  sq.  ft.);  additional  plys,  $1.50  to  $2.50 
per  square;  vertical  surfaces  add  10  per  cent  to  25  per  cent. 

J. — Cold  process,  felt  or  burlap,  same  as  commercial  asphalt. 

K. — Pressure  work,  i  ply,  $4  to  $5  per  square. 

L. — Commercial  asphalt  and  asphalt  felt,  add  15  per  cent  to 
60  per  cent  per  ply,  depending  upon  conditions. 

L. — Special  asphalts  and  felts,  add  30  per  cent  to  50  per  cent  per 
ply. 

M. — Asphalt  mastic,  i  in.,  15  cents  per  square  foot. 


[374] 


COMPOSITION  OF  SOME  OF  THE  WATER- 
PROOFING COMPOUNDS  IN  USE.* 

In  the  " Sylvester's  process"  a  hot  solution  of  soap,  prepared  by 
dissolving  J  Ib.  of  Castile  soap  in  i  gallon  of  water,  is  first  brushed 
over  and  into  the  surface  of  the  concrete,  and  allowed  to  dry  for 
24  hours.  At  the  end  of  that  period  a  second  wash,  consisting  of 
2  oz.  of  alum  dissolved  in  i  gallon  of  water,  is  applied  in  the  same 
manner.  The  alum  solution  should  be  at  a  temperature  of  from 
60°  to  70°  Fahr.  (See  also  page  367.) 

In  "  Handbook  for  Superintendents  of  Construction,  etc.,"  the 
following  cement  wash  is  recommended  for  making  a  water-tight 
lining  for  cisterns:  A  stock  solution  is  prepared  of  i  Ib.  "lye,"  5  Ib. 
alum  dissolved  in  2  quarts  of  water.  One  pint  of  this  solution  is 
stirred  into  a  pail  of  water  containing  10  Ib.  of  cement,  and  the 
mixture  is  applied  to  the  surface  of  the  concrete  with  a  brush. 

Another  method  is  to  apply  a  rendering  composed  as  follows: 

1.  Portland  cement  i  part,  sand  i  part. 

2.  Portland  cement  i  part,  sand  2  parts,  lime  paste  J  part. 

3.  Portland  cement  i  part,  sand  3  parts,  lime  paste  i  part. 

4.  Portland  cement  i  part,  sand  5  parts,  lime  paste  ij  parts. 

The  surface  of  the  rendering,  composed  according  to  one  of  the 
above  formulas,  is  brushed  with  a  solution  of  i  Ib.  "  concentrated  lye," 
5  Ib.  alum,  and  2  gallons  water,  in  the  proportion  of  i  pint  of  this  solu- 
tion to  5  Ib.  of  cement. 

In  principle  the  above-named  methods  are  alike,  and  all  depend 
upon  the  precipitation  within  the  surface  pores  of  the  concrete,  or 
outer  coat,  of  insoluble  alum-  soap,  or  hydrate  of  alumina,  or  both 
together.  The  last-named  example,  however,  combines  to  some 
extent  the  method  of  pore-filling  in  bulk  with  sand  and  lime  paste. 

In  "  Plastering,  Plain  and  Decorative,"  Miller  recommends  paint- 
ing the  surface  of  the  work  with  a  hot  mixture  prepared  by  mixing 

*  Compiled  in  part  by  Gadd. 

[-375] 


Handbook  for  Cement  and  Concrete  Users 

20  lb.  of  chopped  suet  with  i  bushel  of  lime,  and  stirring  up  with  boil- 
ing water. 

Professor  Hatt  states  that  with  a  mortar  composed  of  i  part  of 
cement  to  2^  parts  of  bituminous  ash,  when  alum  and  soap  were 
mixed  with  the  water  used  for  gauging,  the  strength  and  hardness  in- 
creased 50  per  cent,  and  absorption  decreased  by  the  same  amount. 
One-half  of  the  water  used  for  gauging  was  a  5-per-cent.  solution  of 
ground  alum,  and  the  other  half  was  a  y-per-cent.  solution  of  soap. 
The  alum  solution  was  used  first. 

Cunningham  proceeds  on  similar  lines.  He  uses  powdered  alum 
equal  to  i  per  cent,  of  the  combined  weight  of  sand  and  cement. 
To  the  water  used  in  the  mix  he  adds  i  per  cent,  of  yellow  soap. 

Hawley  employed  a  stock  solution  of  2  lb.  caustic  potash,  5  lb. 
powdered  alum,  and  10  quarts  water.  A  finishing  coat  was  made 
with  3  quarts  of  this  solution  in  each  batch  of  mortar  containing  2 
bags  of  cement.  The  mortar  was  made  with  2  volumes  of  sand  to 

1  of  cement,  and  the  work  covered  to  a  depth  of  ^  in. 

Marsh  gives  the  following  as  a  waterproof  coat  or  rendering: 

2  lb.  soft  soap,  12  lb.  alum,  30  gallons  water  per  cu.  yd.  of  the  mor- 
tar.    Or,  2  lb.  caustic  potash,  5  lb.  alum,  10  quarts  water.     Of 
this  solution  3!  quarts  are  used  for  2  bags  of  cement  and  twice  its 
volume  of  sand. 

It  will  be  observed  that  these  processes  again  depend  upon  the 
precipitation  of  aluminum  soap  or  of  hydrated  oxide  of  aluminum, 
the  only  difference  being  that,  in  these  cases,  the  precipitate  is  mixed 
with  the  mortar  instead  of  being  deposited  at  the  surface  of  the 
hardened  material. 

Gaines,  in  a  paper  recently  published,  states  that  watertight  con- 
crete can  be  made  (i)  by  replacing  the  mixing  water  with  a  dilute 
solution  of  a  suitable  " electrolyte"  (i.e.,  a  i-per-cent.  or  2-per-cent. 
solution  of  alum);  (2)  by  replacing  5  per  cent,  to  10  per  cent,  of 
the  cement  with  dried  and  finely  ground  colloidal  clay;  (3)  by  combin- 
ing methods  (i)  and  (2).  With  regard  to  the  second  of  these  proc- 
esses the  action  appears  to  be  simply  one  of  pore-filling  with  fine 
particles  of  clay,  inasmuch  as  no  "electrolyte"  is  used;  and  in  the 
other  cases  it  is  probable  that  the  same  kind  of  action  takes  place  by 
precipitation  of  alumina,  from  the  "electrolytic"  solution,  by  calcium 
hydroxide,  whether  the  electrolytic  theory  itself  be  correct  or  not. 

[3761 


Waterproofing  Compounds  in  Use 

It  may  be  remarked  that  the  use  of  pulverized  clay  for  this  pur- 
pose is  old. 

"Lux,"  Patent  No.  4606  of  1904.  This  material  is  prepared  by 
pouring  over  100  kilos  of  cement  clinker  (unground)  10  litres  of 
boiling  water  containing  245  grams  of  stearine,  12  grams  of  potash 
(presumably  caustic  potash,  although  it  is  not  clearly  stated),,  and  10 
grams  of  colophony  (i.e.,  common  resin). 

Gallagher's  Waterproof  Compound. — This  material  is  to  be  added 
to  cement  in  the  proportion  of  2  per  cent,  to  5  per  cent,  on  the  weight 
of  dry  cement  before  mixing  with  the  sand  and  water.  Its  com- 
position has  been  stated  to  be  chiefly  lime  and  magnesia,  with  about 
3  per  cent,  of  stearine  or  other  fatty  acid. 

11  Pharos"  waterproofing  compound  is  composed  of  the  following: 

PER  CENT. 

Free  fat  (tallow  or  stearine) 20.22 

Lime  soap     Combined  fatty  anhydrides I4-55 

Combined  lime 1.57 

Lime 3°  •  45 

Magnesia 21.15 

Hygroscopic  water 3-32 

Combined  water 5.77 

Silica .  1.17 

Alumina  and  ferric  oxide  ... i .  18 

Sulphuric  anhydride,  etc 62 


100.00 


Cold  bituminous  damp-proof  paints,  such  as  Horn's  Dehydratine, 
Toch's  R.  I.  W.,  Antihydrine,  etc.,  for  use  on  the  interior  surfaces 
of.  exposed  walls  or  for  exterior  of  foundations  not  subject  to  water- 
pressure.  These  are  made  up  of  specially  selected  asphalts  dissolved 
in  carbon  bisulfide  or  some  kindred  hydrocarbon,  the  proportions 
varying  according  to  the  use  to  which  same  is  to  be  put. 

Parafrme,  or  other  mineral  substances,  dissolved  in  gasolene  with 
the  addition  of  resin  as  a  hardening  agent,  proportions  varying  ac- 
cording to  use.  This  is  employed  for  surface  application  to  walls, 
etc.,  that  are  to  be  rendered  water-tight.  Trade  names:  Dehydra- 
tine, Waxol,  Anhydrol,  etc. 

Medusa,  Hydratite,  Maumee,  Whitehall,  Keystone,  McCormick, 
Toxement,  etc.,  and  similar  powders  in  very  finely  divided  state. 
These  are  metallic  stearates  or  resinates,  to  which  are  added  .vary- 

[377] 


"•  •  •*•*•  •    i  i**0 :'«;  '*"•:  l/\ 

Handbook  for  Cement  and  Concrete*  User's 

ing  proportions  of  hydrated  lime,  alum,  and  clay.  Two  to  five  per 
cent,  of  the  compound  is  usually  added  to  i  bag  of  cement  before  the 
addition  of  water 

Ceresit,  Lapidas,  Truscon,  Aquabar,  Leaw's  Compound,  etc., 
are  combinations  of  lime  soaps  or  oil  emulsions,  the  product  being 
added  to  the  water  employed  for  tempering  the  cement. 

Ironite,  a  metallic  iron  waterproofing  compound,  is  one  of  the 
latest  additions  to  the  list.  Its  principal  ingredient  is  a  very  finely 
divided  iron,  which  on  exposure  to  water  oxidizes  and  expands, 
filling  the  voids.  It  probably  contains,  in  addition  to  the  iron,  some 
Portland  cement  and  sal  ammoniac.  Mixed  with  water  and  used  as 
slush  coat  or  mixed  dry  with  cement. 

A  number  of  waterproof  cement  coatings  are  now  being  marketed 
under  such  trade  names  as  Symentrex,  Blanchite,  Glidden's,  Cabot's, 
Trusscpn,  etc.  These  are  paints  applied  to  concrete,  the  material 
being  constructed  to  give  an  artistic  waterproof  surface  and  not  to 
saponify  when  applied  to  same. 


BIBLIOGRAPHY. 

Text-Books: 

Concrete,  Plain  and  Reinforced,  by  Homer  A.  Reid. 

Gillette's  Handbook  of  Cost  Data. 

Kidder's  Architect's  Pocketbook. 

Patton  on  Foundation. 

Patton's  Civil  Engineering. 

Building  Construction,  by  Prof.  Henry  Adams. 

Baker's  Masonry  Construction. 

Buel  and  Hill's  Reinforced  Concrete. 

Kidder's  Building  Superintendence  and  Construction. 

Cairn's  Cement  and  Concrete. 

Brown's  Handbook  for  Cement  Users. 

Taylor  and  Thompson  Reinforced  Concrete. 

Marsh  on  Reinforced  Concrete. 

Thurston  on  Materials  of  Construction. 

The  Prevention  of  Dampness  in  Houses,  by  A.  F.  Keim. 

The  Waterproofing  of  Fabrics,  by  Mierzinski. 

Henley's  2oth  Century  Book  of  Formulas  and  Recipes. 

Richardson  on  Asphalt. 

Boorman  on  Asphalts . 

American  Civil  Engineers  Pocket  Book. 

[378] 


Society  Publications: 

Transactions,  Am.  Soc.  C.  E.,  1872,  1884,  1894,  1900,  1903,  1907,  1909, 

1910. 

National  Ass'n  of  Cement  Users,  1906,  1907,  1908,  1909,  1910. 
Am.  Soc.  Testing  Materials,  1906,  1907,  1908,  1909,  1910. 
Western  Soc.  of  Civil  Engineers,  Boston  Society  of  Civil  Engineers. 
Ass'n  of  R.  R.  Superintendents  of  Bridges  and  Buildings,  1908. 
Municipal  Engineers,  City  New  York,  Nov.,  1908. 
Philadelphia  Engineers'  Club,  June,  1908. 

Periodicals: 

Waterproofing,  1007,  1908. 

Engineering  News,  1883,  1891,  1900,  1902,  1903,1904,  1905,  1907,1908. 
Engineering  Record,  1893,  1907,  1908. 

Cement  Era,  Concrete,  Concrete  Age,  Engineering  Digest,  Engineering- 
Contracting,  1907,  1908. 

Miscellaneous : 

War  Dept.  Reports,  1893,  1897,  1898,  1899,  1900. 
Reports  of  U.  S.  Patent  Office  for  the  past  twenty  years. 

[379] 


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